Shiva Purana
बृहस्पतेर्महाबुद्धेर्देवर्षेरंशतो मुने ॥ भरद्वाजात्समुत्पन्नो द्रोणोऽयोनिज आत्मवान् ॥ २ ॥
O sage, though a part of the celestial sage of great intellect Bṛhaspati, the self-possessed and prudent Droṇa was born of Bharadvāja but not of any womb.
english translation
bRhaspatermahAbuddherdevarSeraMzato mune ॥ bharadvAjAtsamutpanno droNo'yonija AtmavAn ॥ 2 ॥
hk transliteration by Sanscript